Research on prediction of WMA mixing temperature or additive dosage using digital image recognition of coating rate

Abstract

It is difficult to determine a reasonable mixing temperature for WMA based solely on the viscosity-temperature relationship of the binder, as is the case for HMA, and it is a more reasonable solution to determine the mixing temperature of WMA by the state of the mix. This paper proposes to use the coating rate as an index for determining the mixing temperature of WMA, to analyze the reliability and sensitivity of this index using a digital image recognition method, and to analyze the influence law of this method based on the coating rate recognition test. The study shows that: The precision of the digital image coating rate recognition test can meet the requirements of calculating the mixing temperature; in a certain range, the coating rate of WMA is positively correlated with the mixing temperature or additive dosage; the sensitive variation of the coating rate with mixing temperature and additive dosage can be used to predict the engineering mixing temperature or additive dosage for WMA; the slope of the coating rate contour also has some common trends and can be used to illustrate the effect of warm mix additives (or warm mix technology) on the effectiveness or efficiency of warm mix.

Keywords

• road engineering
• warm mix asphalt
• coating rate
• digital image
• mixing temperature
• additive dosage